JP2008039745A - Calibration method and calibration device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a calibration device for facilitating execution of calibration, by executing the calibration without using a projection plate. <P>SOLUTION: The calibration device is provided with first drive mechanisms 21 and 21 for moving the direction of irradiating pattern light of projectors 1 and 1, a second drive mechanism 22 for moving the imaging direction of a camera 2, and a control unit CU for operating both the drive mechanisms 21 and 22. The control unit CU adjusts positions of the right and left directions of the camera 2, based on a horizontal movement speed of slit light on an image imaged by the camera 2 and the position on the image during detecting pitching. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a calibration method and a calibration apparatus that corrects a deviation from a normal position of at least one of a light projecting unit side and an image capturing unit side by imaging pattern light emitted from a light projecting unit with an image capturing unit.

Conventionally, using a projection plate on which a lattice-like figure similar to the slit light to be irradiated is drawn, the state in which light is irradiated toward the projection plate is imaged by the light receiving device, and the position of the projection plate is moved repeatedly. There is known a device for calibrating a light projecting device and a light receiving device (see, for example, Patent Document 1).
Japanese Patent No. 3421139

  However, in the above-described prior art, in order to perform calibration, a dedicated projection plate is required, and calibration takes time.

  The present invention has been made paying attention to the above-described problems, and provides a calibration method and a calibration apparatus that can perform calibration without using a projection plate and can easily perform calibration. The purpose is to do.

  In order to achieve the above-described object, the present invention captures light of a predetermined pattern irradiated from the light projecting unit by the image capturing unit, detects the moving speed of the captured light and the position of the light on the captured image, A calibration characterized in that a center of gravity position of a light movement vector is obtained from these movement speeds and positions, and calibration is performed to adjust at least one position of the imaging means side and the light projection means side based on the obtained movement vector. Method.

  In the present invention, the barycentric position of the movement vector of the pattern light is obtained from the relationship between the movement vector and the position when the pattern light moves on the imaging screen imaged by the imaging means.

  Then, based on the position of the center of gravity, the position of at least one of the light projecting unit and the image capturing unit is adjusted so that the relative position between the light projecting unit and the image capturing unit has a predetermined relationship.

  As described above, in the present invention, calibration can be performed without using a calibration-dedicated equipment such as a projection plate, and calibration is easier than in the case of using equipment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The calibration apparatus according to this embodiment includes a light projecting unit (1) that irradiates a predetermined pattern of pattern light (PL), an imaging unit (2) that captures an irradiation range of the pattern light (PK), and the pattern. The driving mechanism (21, 22) capable of moving at least one of the irradiation direction of light (PL) and the imaging direction of the imaging means (2), and imaging information is input from the imaging means (2), and the driving Control means (CU) for controlling the operation of the mechanism (21, 22), and the control means (CU) includes a moving speed of the pattern light (PL) on the picked-up image of the image pickup means (2) and The position of light is detected, the position of the center of gravity of the light movement vector is obtained from the detected movement speed and position, and the drive mechanism (21, 22) is driven on the basis of the obtained movement vector, thereby the light projecting means (1) And a calibration device and performing calibration for adjusting at least one direction of the imaging direction of the pattern light irradiation direction and the image pickup means (2).

  A calibration apparatus according to Example 1 of the preferred embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 2, the calibration device according to the first embodiment is applied to a distance measuring device A mounted on a vehicle MB.

This distance measuring device A measures the distance from the object M existing in the detection target region with the front of the vehicle as the detection target region, and includes a light projecting device (light projecting unit) 1, 1 and a camera (imaging unit). 2 are provided.
The light projecting devices 1 and 1 are mounted separately in the vehicle left-right direction below the front bumper 3 of the vehicle MB.
Further, the camera 2 is not shown in the center of the front end portion of the roof 4 of the vehicle MB, which is the center position in the vehicle width direction of the light projecting devices 1 and 1 and the vehicle upper position than the light projecting devices 1 and 1. The optical axis 2a (see FIG. 1) passing through the imaging center position CE is attached in the vicinity of the rearview mirror so that it faces the front of the vehicle.

  The light projecting device 1 is arranged with the optical axis 1a (see FIG. 1), which is a light projection central axis, facing the front of the vehicle, and the pattern light PL shown in FIG. 3 composed of a plurality of slit-shaped lights is directed toward the front of the vehicle. For example, as shown in FIG. 4, the light source 11, the lens 12, the slit plate 13, and the lens 14 can be arranged in order.

  The slit plate 13 can irradiate the pattern light PL having the shape shown in FIG. 3, and as shown in FIG. 4, the vertical slit 13 a extending in the vertical direction and a plurality of horizontal slits extending perpendicularly thereto. 13b, 13b, 13b, 13b, and oblique slits 13c, 13c, 13c, 13c that obliquely intersect the vertical and horizontal slits 13a, 13b.

  Therefore, as shown in FIG. 3, the vertical slit light PL1, the horizontal slit light PL2, and the oblique slit light (inclined slit light) PL3 are emitted from one light projecting device 1.

The light projecting apparatuses 1 and 1 are installed such that the horizontal slit light PL2 extends in the vehicle left-right direction in the detection target region, and the vertical slit light PL1 is irradiated in a state extended in the vehicle vertical direction. ing.
Therefore, both the longitudinal slit lights PL1 are irradiated in parallel to the front of the vehicle perpendicular to the vehicle left-right direction, which is the separating direction of the light projecting devices 1 and 1.
The horizontal slit light PL2 extends across the detection target area in front of the vehicle in the left-right direction of the vehicle, and a total of four horizontal slit lights PL2, PL2, PL2 and PL2 are obtained by changing the irradiated position in the vehicle front-rear direction. PL2 and PL2 are irradiated. Further, when the left and right light projecting devices 1 and 1 are arranged at the normal positions, the respective lateral slit lights PL2, PL2, PL2 and PL2 emitted from the right and left light projecting devices 1 and 1 are arranged so as to be continuous in a straight line in the vehicle left-right direction. ing.
Further, the oblique slit lights PL3, PL3, PL3, and PL3 are irradiated in an oblique direction so as to intersect with the longitudinal slit light PL1, and two of these are emitted toward the inside of the longitudinal slit light PL1 and the rest. Are irradiated to the outside of the longitudinal slit light PL1.

  Further, in the first embodiment, among the slit lights PL1, PL2, and PL3, those used for calibration are indicated by bold lines in FIG. That is, among the slit light emitted from each light projecting device 1, the vertical slit light PL1, the second horizontal slit light PL2 (K) from the side close to the vehicle MB, and the inner side of the vertical slit light PL1, PL1. The oblique slit light PL3 (K) that is arranged and intersects at the position of the horizontal slit light PL2 (K) is used for calibration.

Returning to FIG. 2, the camera 2 captures a luminance image using an imaging element (pixel) such as a CCD (Charge Coupled Devices) or a CMOS (Complementary Metal Oxide Semiconductor) (not shown), and is a detection target region. Take an image of the front of the vehicle.
An example of imaging by the camera 2 is shown in FIG. 5, and the image PC shows a state in which the pattern light PL is irradiated and the object M exists on the imaged road surface RD.

  Information obtained by imaging with the camera 2 is input to the control unit CU shown in FIG. The control unit CU receives signals from the camera 2 and other in-vehicle sensors, detects the object M, and measures the distance to the object M. The RAM (Random Access Memory) and ROM (Read) are not shown. It is a well-known one having only memory (CPU), central processing unit (CPU), and the like.

  Briefly explaining this, the light projecting devices 1, 1 and the camera 2 are arranged at preset positions of the vehicle MB, and the respective slit lights PL1, PL2 when the pattern light PL is irradiated in front of the vehicle MB. , PL3 and the relative position of vehicle MB are known in advance. That is, as shown in the image PC of FIG. 5 as an example of imaging, the object M with respect to the vehicle MB is based on the relative position between the pattern light PL irradiated on the road surface RD and the object M present on the road surface RD. The position can be measured. For example, the object M on the image PC is present at a position slightly to the left of the front of the vehicle MB that is the intersection of the vertical slits PL1 and PL1, and the distance indicated by the lateral slit light PL2 disposed farthest away. It can be seen that it exists farther than. From such a relative relationship, the position of the object M can be measured.

Furthermore, the control unit CU operates the first drive mechanisms 21 and 21 that move the optical axis 1a of the light projecting device 1 and the second drive mechanism 22 that moves the optical axis 2a of the camera 2 to operate each optical axis. Calibration control for adjusting the positions of 1a and 2a is executed.
That is, the light projecting device 1 is supported so as to be able to turn in the horizontal direction around the vertical turning shaft 21a facing the vehicle vertical direction, and up and down around the horizontal turning shaft 21b facing the vehicle width direction. It is supported to be movable in the direction. The first drive mechanism 21 includes a motor 21c that transmits a driving force so that the light projecting device 1 rotates in the horizontal direction about the vertical rotation shaft 21a, and the light projection device 1 centers on the horizontal rotation shaft 21b. And a motor 21d for transmitting a driving force so as to rotate in the vertical direction.

Similarly, the camera 2 is also supported so as to be able to turn in the horizontal direction around the vertical turning shaft 22a facing the vehicle up-down direction, and up and down around the horizontal turning shaft 22b facing the vehicle width direction. It is supported so as to be movable. The second drive mechanism 22 includes a motor 22c that transmits a driving force so that the camera 2 rotates in the horizontal direction about the vertical rotation shaft 22a, and a camera 2 that moves in the vertical direction about the horizontal rotation shaft 22b. And a motor 22d for transmitting a driving force so as to rotate.
In the calibration control, the control unit CU appropriately operates the motors 21c, 21d, 22c, and 22d of the drive mechanisms 21, 21, and 22 to adjust the vertical and horizontal positions of the optical axes 1a and 2a. The vertical direction of the optical axes 1a and 2a is synonymous with the vertical direction of the vehicle MB, and the horizontal direction of the optical axes 1a and 2a is synonymous with the horizontal direction of the vehicle when facing the front of the vehicle MB. is there.

  The vehicle behavior detecting means 5 is connected to the control unit CU in order to execute this calibration control. The vehicle behavior detection means 5 detects the behavior of the vehicle MB, and includes a vehicle speed sensor, a G sensor, a yaw rate sensor, etc. (not shown), and detects vehicle speed, vehicle pitching, roll, yawing, and the like.

  Next, the flow of calibration control processing by the control unit CU will be described with reference to the flowchart of FIG. In the first embodiment, the calibration control is executed periodically and also when a preset switch operation is executed. Here, the term “regular” may be executed based on a preset time such as one week or one month, or the travel distance may be 100 km or several hundred km, for example. It may be executed every time a predetermined distance is reached.

  In step S1, light is projected by the light projecting device 1, and in the next step S2, imaging by the camera 2 is performed.

  In step S3, the vehicle behavior detected by the vehicle behavior detection means 5 is read. In the subsequent step S4, it is determined whether or not the vehicle behavior is only pitching. When only pitching occurs, the process proceeds to the next step S5. If not, the process returns to step S3.

  In step S5, the horizontal moving speed of the oblique slit light PL3 (K) on the image is calculated, and in step S6, the horizontal position of the optical axis 2a of the camera 2 is calculated.

  If this calculation is further described, the moving speed is determined by the oblique slit light PL3 existing in the speed calculation area PCL arranged in a horizontal line set on the image PC as shown in FIGS. 7 (a) and 7 (b). Calculated with the moving speeds v1 and v2 in (K). That is, when pitching occurs in the vehicle MB, the oblique slit light PL3 (K) moves up and down on the image due to the difference in height between the light projecting devices 1 and 1 and the camera 2, but at this time, for speed calculation In the region PCL, the left and right oblique slit lights PL3 (K) are displaced in the horizontal direction as indicated by arrows in FIG.

  Therefore, as shown in FIG. 5C, the time for the oblique slit light PL3 (K) to move sequentially from the image sensor (pixel) pc (n) to the adjacent image sensor pc (n + 1) is calculated. The moving speeds v1 and v2 are obtained.

Then, the gravity center position GP of the two speed vectors is calculated from the relationship between the horizontal moving speeds v1 and v2 of the left and right oblique slit lights PL3 (K) and the position of the image sensor.
For example, as shown in FIG. 5B, assuming that the speeds of the left and right oblique slit lights PL3 (K) are v1 and v2, respectively, and the positions of the imaging elements are L1 and L2, respectively, these are v1: v2 = L2: L1 and GP indicates the position of the center of gravity in the figure.
The center of gravity position GP is a normal left-right position of the optical axis 2a of the camera 2, and in step S6, the position of the center of gravity GP is obtained as the left-right position of the optical axis 2a.

  Incidentally, the center of gravity position GP is calculated based on a movement vector generated by the movement of the oblique slit light PL3 (K). Therefore, when only the optical axis 2a of the camera 2 is shifted in the left-right direction, the vehicle The center of gravity of the velocity vector of the left and right oblique slit light PL3 (K) in either case where the optical axes 1a of the left and right light projecting devices 1 and 1 are shifted or both the optical axes 1a and 2a are shifted. The position GP indicates the position of the regular optical axis 2 a of the camera 2.

  Next, in step S7, the motor 22c of the second drive mechanism 22 is driven to adjust the position of the optical axis 2a of the camera 2 in the left-right direction (horizontal direction).

  Next, in step S8, the vertical and horizontal shifts of the left and right light projectors 1, 1 are calculated. Among the vertical and horizontal shifts, the horizontal shift is a shift with respect to the normal position, while the vertical shift is a relative shift between the left and right light projecting devices 1 and 1.

When the left and right light projecting apparatuses 1 and 1 are arranged at the normal positions, the left and right lateral slit lights PL2 are continuously arranged in a straight line in the horizontal direction as shown in FIGS. 3 and 8D. Arranged.
However, when the optical axis 1a of the left light projecting device 1 is shifted downward in the vehicle, as shown in FIGS. 8 (a1) and (a2), the lateral slit light PL2 does not continue in a straight line, and the left side In the vertical direction occurs between the horizontal slit light PL2.
When the optical axis 1a of the left light projecting device 1 is shifted to the left, as shown in FIGS. 8 (b1) and (b2), the lateral slit light PL2 does not continue on a straight line, but on the left side. The lateral slit light PL2 is inclined obliquely.
Further, when the optical axis 1a of the left light projecting device 1 is shifted upward and leftward, as shown in FIGS. 8 (c1) and (c2), the lateral slit light PL2 does not continue on a straight line. Furthermore, the left side slit light PL2 is shifted upward and tilted obliquely.

  Therefore, in step S8, when the left and right horizontal slit lights PL2 (K) are not continuous in a straight line and both are displaced, the relative displacement in the vertical and horizontal directions is calculated.

  In step S9, the motors 21c and 21d of the first drive mechanism 21 are driven based on the deviation obtained in step S8 so that the lateral slit light PL2 continues in a straight line as shown in FIG. 8D. The horizontal position and the relative vertical position of the projectors 1 and 1 are adjusted relative to the normal position.

Next, in step S10, an imaging center position CE that is the position of the optical axis 2a of the camera 2 is calculated. As shown in FIG. 9B, the imaging center position CE of the camera 2 coincides with the vanishing point LP where the longitudinal slit light PL1 intersects. In this step S10, the vanishing points of the longitudinal slit lights PL1 and PL1. The center position in the left-right direction of LP is calculated as the imaging center position CE.
Note that the position of the light projecting device 1 in the left-right direction has already been adjusted to the normal position in step S8, so the vanishing point LP matches the imaging center position CE.
In the next step S11, the motor 22d of the second drive mechanism 22 is driven so that the optical axis 2a (imaging center position CE) of the camera 2 coincides with the vanishing point LP. Make adjustments.

Next, in step S12, the amount of vertical displacement of the light projecting devices 1 and 1 with respect to the normal position is calculated. As shown in FIG. 10, the vertical shift amount of the light projecting devices 1 and 1 compares the distance H between the center of the optical axis 2a of the camera 2 and the lateral slit light PL2 (K) with a predetermined distance. Ask for it.
In the next step S13, the shift amount obtained in step S12 is eliminated, and the first driving mechanism 21 is operated so that the interval H becomes the set interval, so that the light projecting devices 1 and 1 are moved in the vertical direction. Adjust the position.

Next, the operation of the first embodiment will be described.
In the first embodiment, when calibration control is started periodically or by a start operation, irradiation of the pattern light PL by the light projectors 1 and 1 and imaging by the camera 2 are started (steps S1 and S2).

Next, the adjustment of the orientation of the optical axes 1a, 1a of the light projecting devices 1, 1 and the optical axis 2a of the camera 2 is started. First, the horizontal position adjustment of the optical axis 2a of the camera 2 is performed.
In the first embodiment, the adjustment of the position of the optical axis 2a of the camera 2 in the left-right direction is performed by using the fact that the optical axes 1a, 1a of the left and right light projecting devices 1 move up and down synchronously by pitching the vehicle.
That is, to calculate the imaging center position CE of the camera 2 as described later, the fact that the left and right oblique slit lights PL3 (K) move up and down in synchronization is used. Accordingly, when the vehicle behavior detected by the vehicle behavior detection means 5 is read and the vehicle behavior is only pitching without rolling or yawing components, the left and right direction of the camera 2 moves in the left-right direction. Position adjustment is started (steps S3 and S4).

  In the adjustment of the position of the optical axis 2a of the camera 2, first, as the oblique slit light PL3 (K) moves up and down, the speed of moving in the left-right direction in the speed calculation region PCL that is a horizontal row of image sensor rows. Is calculated (step S5).

Further, based on this moving speed and the position of the oblique slit light PL3 (K) in the speed calculation area PCL, a movement vector of the oblique slit light PL3 (K) is obtained, and the center of gravity position GP is determined as the optical axis of the camera 2. 2a is calculated as the horizontal position (step S6).
Then, the motor 22c of the second drive mechanism 22 is driven so that the horizontal position of the optical axis 2a of the camera 2 coincides with the obtained horizontal position (center of gravity position GP), and the horizontal direction of the camera optical axis. Position adjustment is performed (step S7).

  When the adjustment of the position of the optical axis 2a of the camera 2 in the left-right direction is completed in this way, the adjustment of the left-right direction and the relative vertical position of the light projecting devices 1 and 1 is performed next.

  In this case, the shift of the left and right lateral slit light PL2 (K) is calculated from the image PC of the pattern light PL (step S8). Then, the first drive mechanisms 21 and 21 are arranged such that the left and right lateral slit lights PL2 (K) and PL2 (K) are continuously straight in the horizontal direction as shown in FIG. Motors 21c, 21c, 21d, and 21d are driven to adjust the horizontal positions of the optical axes 1a and 1a of the light projecting devices 1 and 1 to normal positions, and the vertical positions are the same height on the left and right. Make adjustments.

Next, the vertical adjustment of the optical axis 2a of the camera 2 is performed.
In this case, the position of the optical axis 2a of the camera 2 (the imaging center position CE on the image PC is made to coincide with the vanishing point LP of the longitudinal slit light PL1 of the light projecting devices 1 and 1 that have already been correctly adjusted in the left-right direction. The motor 22d of the second drive mechanism 22 is driven to adjust the vertical position of the optical axis 2a (steps S10 and S11).

Next, the vertical positions of the optical axes 1a and 1a of the light projecting devices 1 and 1 are adjusted.
In this case, the heights of the optical axes 1a and 1a of the light projecting devices 1 and 1 are set based on the height of the imaging center position CE on the image PC whose position has already been adjusted. First, the imaging center position CE is set. Then, the difference (deviation amount) from the height of the horizontal slit light PL2 (K) is obtained (step S12). Then, the motors 21d and 21d of the first drive mechanisms 21 and 21 are driven so that the deviation amount becomes a preset amount, and the vertical position adjustment of the optical axes 1a and 1a of the light projecting devices 1 and 1 is performed. I do.

  As described above, the optical axes 1a, 1a, and 2a of the light projecting devices 1 and 1 and the camera 2 are arranged at the normal positions set in advance in the vertical and horizontal directions, and the calibration control is finished.

As described above, in the first embodiment, calibration can be performed without using calibration equipment such as a projection plate, and calibration can be easily performed.
Further, in the first embodiment, calibration is automatically performed during traveling in the apparatus mounted on the vehicle MB, and calibration can be performed more easily. By the way, when a projection plate is used as in the prior art, it is difficult for the user of the vehicle MB to calibrate himself / herself. For example, it is necessary to bring the vehicle MB to a repair shop or the like. , Without user trouble and excellent versatility.
Moreover, in the first embodiment, since the projectors 1 and 1 are moved up and down in synchronism using the pitching of the vehicle MB, the projectors 1 and 1 are used by using the first drive mechanisms 21 and 21. Compared with moving up and down 1 in synchronization, the irradiation light (pattern light PL) can be moved up and down easily and reliably in a synchronized manner. Further, since no power is used at this time, an energy saving effect can be obtained.

  In addition, as the order of calibration, first, the position of the optical axis 2a of the camera 2 in the left-right direction is adjusted. In this case, the optical axis 2a (imaging center position CE) of the camera 2 is obtained by obtaining the center of gravity position GP based on the movement vector of the oblique slit light PL3 (K) even if the optical axis 1a of the light projecting device 1 is shifted. Can be adjusted to the correct position. Therefore, calibration is possible without using equipment such as a projection plate as described above.

Further, as the order in which calibration is performed, the horizontal position adjustment of the camera 2 is first performed as described above, and then the horizontal position adjustment and the relative vertical position adjustment of the light projecting devices 1 and 1 are performed, Next, the vertical position adjustment of the camera 2 is performed, and then the vertical position adjustment of the light projecting apparatuses 1 and 1 is performed. By using such an order, it is possible to accurately adjust the position.
That is, by first adjusting the position of the camera 2 in the left-right direction, the fact that the left-right direction and the relative vertical position of the light projecting devices 1, 1 are arranged at the correct positions is indicated by the horizontal slit light PL2 on the image PC. It can be recognized that (K) continues in a horizontal straight line. Next, the position of the imaging center position CE can be set based on the vanishing point LP of the projectors 1, 1 by adjusting the position of the camera 2 and the projectors 1, 1 in the left-right direction. Next, the height of the projectors 1 and 1 can be adjusted by adjusting the vertical position of the camera 2.

  Next, a calibration apparatus B according to Example 2 of the embodiment of the present invention will be described with reference to FIGS. In the description of the second embodiment, the same or equivalent parts as those in the first embodiment will be denoted by the same reference numerals and different parts will be mainly described.

  The calibration apparatus B of the second embodiment is an example in which the distance measuring apparatus 100 that emits an electromagnetic wave such as a millimeter wave, receives a reflected wave from an object, and measures the distance to the object is used for calibration. is there.

That is, as shown in FIG. 11, the distance measuring device 100 includes an electromagnetic wave transmitting device 101 that emits an electromagnetic wave, and a receiving device 102 that receives a reflected wave of the electromagnetic wave emitted from the electromagnetic wave transmitting device 101. .
And the calibration apparatus B of Example 2 performs the calibration which arrange | positions the electromagnetic wave transmitter 101 and the receiver 102 in a regular position.

Therefore, the calibration device B according to the second embodiment includes a first drive mechanism 221 that can rotate the electromagnetic wave transmission device 101 in the vehicle left-right direction and the vehicle up-down direction about the vertical rotation shaft 221a and the horizontal rotation shaft 221b. The receiver 102 controls the drive of the second drive mechanism 222 and the drive mechanisms 221 and 222 that can rotate in the vehicle left-right direction and the vehicle up-down direction about the vertical rotation shaft 222a and the horizontal rotation shaft 222b. Control means 230.
Each of the drive mechanisms 221 and 222 includes the same motors 221c, 221d, 222c, and 222d as in the first embodiment.
Further, the calibration device B of the second embodiment includes a light projecting device 201 that is coaxially fixed to the vertical rotation shaft 221a in the electromagnetic wave transmission device 101, and an imaging that is coaxially fixed to the reception device 102 and the vertical rotation shaft 222a. Device 202.

  The light projecting device 201 is provided at the center in the vehicle width direction in the front bumper 3 shown in the first embodiment, and the slit light constituting the pattern light PL is set differently from the first embodiment. That is, in the first embodiment, as shown in FIG. 12, two vertical slit lights PL1 and PL1 extending in front of the vehicle and a horizontal direction orthogonal to the vertical slit light PL1 from one light projecting device 201. One horizontal slit light PL2 extending in the direction and two oblique slit lights PL3 intersecting with the vertical slit light PL1 and extending symmetrically with the vertical slit light PL1 are irradiated.

  Therefore, in the second embodiment, similarly to the first embodiment, when pitching occurs, the pattern light PL is irradiated from the light projecting device 201, and this is picked up by the image pickup device 202, and the oblique slit light PL2 in the speed calculation region PCL. , PL2 is obtained in the lateral movement speed and position, and the center of gravity position GP of the movement vector is obtained.

  Then, the horizontal position of the imaging device 202 is adjusted so that the imaging center position CE of the imaging device 202 matches the gravity center position GP.

  Next, the left-right position of the light projecting device 201 is adjusted so that the vertical slit terms PL1, PL1 are arranged symmetrically with respect to the imaging center position CE.

  Next, the height of the imaging device 202 is adjusted based on the vanishing point LP of the longitudinal slit lights PL1 and PL1.

  Next, the vertical position of the light projecting device 201 is adjusted so that the horizontal slit light PL2 is horizontally arranged at a predetermined height of the image PC.

  Through the above processing, calibration is performed in which the positions of the light projecting device 201 and the imaging device 202 are arranged at regular positions with respect to the vehicle MB. Calibration is performed to place the device 102 in the normal position.

  In the second embodiment, the imaging device 202 can be used together with the distance measuring device 100 to detect an object in front of the vehicle, but is provided only for calibration of the electromagnetic wave transmitting device 101 and the receiving device 102 described above. You can also.

  As described above, the embodiment of the present invention and Examples 1 and 2 have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment and Examples 1 and 2, and the present invention is not limited thereto. Design changes that do not depart from the gist are included in the present invention.

  That is, in the first and second embodiments, the calibration apparatus and the calibration apparatus according to the present invention are mounted on a vehicle and executed, but the present invention is not limited to this. For example, the present invention can be applied to other vehicles such as railways and ships, robots such as industrial robots, security robots, and nursing robots, or moving devices such as industrial equipment, and can also be applied to fixedly measuring equipment.

  In addition, the light emitted from the light projecting unit is not limited to the pattern light PL in the form shown in the first embodiment, and the light in the optimum form according to the applied device, the detection target region, and the detection target. May be irradiated.

Further, in the first and second embodiments, the example in which the pitching of the vehicle MB is used to synchronize and move the oblique slit light (inclined slit light) PL3 (K) up and down is described. The light projecting apparatuses 1 and 1 may be moved up and down using a driving means such as 21, or the slit plate and the light source may be moved up and down.
Further, when the light projecting devices 1 and 1 are moved using the driving means in this way, the moving direction is not limited to the vertical direction, and the present invention can be applied even if the light projecting devices 1 and 1 are moved in the horizontal and diagonal directions. can do.

When the light projecting unit is moved by the driving unit separately from the image capturing unit, the height of the image capturing unit (camera 2) is set to the light projecting unit (light projecting device 1, 1) as in the first and second embodiments. They may be arranged at the same height without being arranged differently. That is, when the light projecting unit and the image capturing unit are mounted on a vehicle, the direction of the optical axis changes at the same time. Therefore, if the light projecting unit and the image capturing unit are arranged at the same height, the relative movement of the inclined slit light hardly occurs and it is difficult to obtain the movement vector. . On the other hand, when the light projecting means is moved independently, the relative movement amount of both optical axes is large even if they are arranged at the same height, and it is easy to obtain the movement vector of the inclined slit light. .
Furthermore, the inclined slit light that moves up and down in synchronization with the above is only required to generate a moving component in the left-right direction when moving up and down on the screen. For example, the vertical slit light PL1 is used as the inclined slit light. It can also be used.

  In the first embodiment, the light projecting device 1 as the light projecting unit is disposed in the horizontal direction with the camera 2 as the image capturing unit interposed therebetween, and the pattern light is moved up and down when adjusting the center line of the image capturing unit. An example is shown. However, the arrangement of the imaging means and the light projecting means and the direction in which the slit light is moved in synchronization are not limited to this, particularly when applied to means other than the vehicle as described above. For example, the light projecting means can be arranged up and down across the image pickup means, and can be moved synchronously in the left-right direction when adjusting the center line of the image pickup means. Alternatively, the direction of the optical axis of the imaging unit and the light projecting unit directed toward the detection target area is directed downward, the light projecting unit is separated in the front-rear direction or the left-right direction, and the inclined slit light is synchronously moved in the orthogonal direction of the separation direction. You may do it.

  The light projecting unit is not limited to that shown in the first embodiment as long as it can irradiate the pattern light. For example, the light projecting unit irradiates the lens with the slit light without providing the slit plate 13. Or a light source that can irradiate each slit light may be used. In this case, the color may be different for each type of slit light.

  Further, in the first embodiment, when the vertical position of the optical axis 2a of the camera 2 is adjusted, the position of the imaging center position CE on the image PC is made to coincide with the vanishing point LP of the vertical slit light PL1. For example, the imaging center position CE may be made to coincide with a position above or below the vanishing point LP by a predetermined amount.

  Further, in the first and second embodiments, an example is described in which the present invention is applied to a distance measuring device that measures the distance of an object in front of a vehicle, but devices other than the distance measuring device, for example, roadside lines and centerlines drawn on a road The present invention can also be applied to a white line detection device that picks up images and detects them.

  In an apparatus having an imaging unit such as this white line detection apparatus, a light projecting apparatus can be added to perform the calibration of the present invention. Further, in this case, calibration of the light projecting device is not necessary, the calibration of the imaging unit may be executed, and only the driving mechanism that changes the position of the imaging unit may be installed as the driving mechanism.

  Or, conversely, in a device having a light projecting unit, such as a device that irradiates the position of the obstacle with laser light and makes the driver recognize the presence of the obstacle, The present invention can also be applied by adding imaging means.

In this case, the calibration for the imaging unit shown in the embodiment can be omitted, and only the calibration of the light projecting unit can be executed.
That is, when the center of gravity position of the movement vector of the pattern light is obtained, the position of the light projecting means is adjusted so that the center of gravity position is arranged at a predetermined position on the image, and then the pattern light is set to a position set in advance on the image. Calibration can be performed by adjusting the position so that they are arranged.

  Furthermore, as shown in the second embodiment, in an apparatus that does not include a light projecting unit and an image capturing unit, the present invention can be applied to a calibration target by fixing the light projecting unit and the image capturing unit. The application target is not limited to the distance measuring device shown in the second embodiment.

It is the schematic which shows the structure of the calibration apparatus of Example 1 of embodiment of this invention. 1 is a perspective view showing a distance measuring device A to which a calibration device of Example 1 of an embodiment of the invention is applied and a vehicle MB equipped with the same. It is a top view which shows the pattern light PL irradiated from the calibration apparatus of Example 1 of embodiment of this invention. It is structure explanatory drawing which shows the outline of the structure of the light projection apparatus 1 of the calibration apparatus of Example 1 of embodiment of this invention. It is explanatory drawing which shows image PC imaged with the camera 2 of the calibration apparatus of Example 1 of embodiment of this invention. It is a flowchart which shows the flow of the process of the calibration control in control unit CU of the calibration apparatus of Example 1 of embodiment of this invention. It is explanatory drawing which calculates | requires gravity center position GP with the movement vector and position when the diagonal slit light PL3 (K) moves up and down in the calibration apparatus of Example 1 of embodiment of this invention, (a) is image PC. An example is shown, (b) shows an example of movement of the oblique slit light PL3 (K) in the speed calculation area PCL in the image PC, and (c) shows an enlarged view thereof. It is explanatory drawing of the adjustment of the up-down / left-right direction position of the light projection apparatus 1 in the calibration apparatus of Example 1 of embodiment of this invention, (a1) is the optical axis 1a of the left light projection apparatus 1 below a vehicle. An example of the pattern light PL in the case of deviation is shown, (a2) shows an example of the image PC when the optical axis 1a of the left light projection device 1 is shifted downward in the vehicle, and (b1) is an example of the left projection. An example of the pattern light PL when the optical axis 1a of the optical device 1 is shifted to the left is shown. (B2) of the image PC when the optical axis 1a of the left projector 1 is shifted to the left. An example is shown, (c1) shows an example of the pattern light PL when the optical axis 1a of the left projector 1 is shifted upward and leftward, and (c2) shows the optical axis of the left projector 1 An example of the image PC when 1a is shifted upward and leftward is shown, and (d) shows the left and right light projecting devices 1. Deviation shows an example of image PC when not occur in 1. It is explanatory drawing of the vertical position adjustment of the camera 2 in the calibration apparatus of Example 1 of embodiment of this invention, (a) is a top view which shows the example of irradiation of pattern light PL, (b) is the It is a figure which shows an example of image PC. It is explanatory drawing of the vertical direction position adjustment of the light projectors 1 and 1 in the calibration apparatus of Example 1 of embodiment of this invention, (a) is a top view which shows the example of irradiation of pattern light PL, ( b) is a diagram showing an example of the image PC. It is the schematic which shows the structure of the calibration apparatus B and distance measurement apparatus of Example 2 of embodiment of this invention. It is a top view which shows the pattern light PL irradiated from the calibration apparatus B of Example 2 of embodiment of this invention.

Explanation of symbols

1 Projection device (projection means)
1a Optical axis 2 Camera (imaging means)
2a Optical axis 5 Vehicle behavior detecting means 21 First driving mechanism 22 Second driving mechanism CE Imaging center position CU Control unit (control means)
GP Center of gravity H Interval LP Vanishing point M Object MB Vehicle PC Image PL Pattern light PL1 Vertical slit light PL2 Horizontal slit light PL2 (K) Horizontal slit light PL3 (K) Diagonal slit light (tilted slit light)
v1, v2 movement speed

Claims (8)

Irradiate a predetermined pattern of light from the light projecting means,
The projected pattern light is imaged by the imaging means,
Detect the movement speed and position of the captured pattern light on the captured image,
Find the center of gravity of the light movement vector from these movement speeds and positions,
A calibration method characterized by performing calibration for adjusting at least one position of the imaging means side and the light projecting means side based on the obtained movement vector. The pattern light of the light projecting unit includes inclined slit light that extends in an oblique direction with respect to a reference line in a direction orthogonal to the position adjustment direction on the captured image,
When determining the position of the center of gravity, the inclined slit light is moved in the extending direction of the reference line on the captured image of the imaging means, and the inclined slit light on the captured image at this time is moved to the reference line. 2. The calibration method according to claim 1, wherein the position of the center of gravity is obtained based on a moving speed and a position in an orthogonal direction. Based on the position of the center of gravity, first, adjust the position in the orthogonal direction of the reference line on the imaging means side,
Next, based on the pattern light on the captured image, adjust the position in the orthogonal direction of the reference line on the light projecting means side,
Next, based on the pattern light on the captured image, adjust the position in the extending direction of the reference line on the imaging means side,
Next, the position in the extending direction of the reference line on the light projecting means side is adjusted based on the relationship between the imaging center position on the captured image and the pattern light. Item 3. The calibration method according to Item 2. A pair of the light projecting means are disposed apart from each other in the horizontal direction,
In the imaging means, the imaging direction is set so that the reference line is directed in a vertical direction perpendicular to the horizontal direction,
Each light projecting means includes an inclined slit light that intersects the reference line on the captured image, a horizontal slit light that extends in the horizontal direction, and an orthogonal direction of the horizontal slit light. Irradiated with longitudinal slit light,
First, both inclined slit lights irradiated from both light projecting means are moved synchronously in the up-and-down direction on the captured image, the moving speed in the horizontal direction of both inclined slit lights on the captured image, and the image Based on the upper position, find the horizontal center of gravity position of the movement vector of both inclined slit light,
Next, based on the position of the center of gravity, the horizontal position of the reference line on the imaging means side is adjusted,
Next, adjust the horizontal position and the vertical relative position on both light projecting means side so that both lateral slit light continues in a straight line in the horizontal direction on the captured image,
Next, the vertical position of the imaging center position is adjusted based on the vanishing point, which is the point where the tips of both longitudinal slit lights converge on the screen,
Next, the vertical position on the light projecting means side is adjusted so that a vertical interval between the imaging center position on the captured image and the horizontal slit light becomes a predetermined interval. Item 4. The calibration method according to Item 3. The light projecting means and the imaging means are mounted on a vehicle,
The calibration method according to claim 4, wherein the horizontal direction adjustment on the imaging unit side is executed when a synchronous vertical movement of the pattern light occurs due to pitching of the vehicle. A light projecting means for irradiating a predetermined pattern light;
Imaging means for imaging the irradiation range of the pattern light;
A drive mechanism capable of moving at least one of an irradiation direction of the pattern light and an imaging direction of the imaging means;
Control means for inputting imaging information from the imaging means and controlling the operation of the drive mechanism;
The control means detects a movement speed and a light position of the pattern light on a captured image of the imaging means, obtains a barycentric position of a light movement vector from the detected movement speed and position, and based on the obtained movement vector The calibration device is characterized in that the drive mechanism is driven to perform calibration to adjust at least one direction of the pattern light irradiation direction of the light projecting means and the imaging direction of the imaging means. A pair of the light projecting means are provided apart from each other in the vehicle width direction so as to be able to irradiate the pair of pattern lights toward the front of the vehicle, and each light projecting means is a reference in the vertical direction on the captured image. It is configured to irradiate inclined slit light that intersects a line, horizontal slit light that extends in the horizontal direction, and vertical slit light that extends in the vertical direction,
The imaging means is arranged at a center position in the vehicle width direction of the pair of light projecting means and at a different height from the light projecting means so that the irradiation range of the pattern light can be imaged.
The drive mechanism is configured to be movable in at least a vehicle up-down direction and a vehicle left-right direction between the pattern light irradiation direction and the imaging direction,
The input means of the control means includes pitching detection means for detecting the pitching of the vehicle,
The control means obtains the gravity center position of the movement vector of the slit light from the moving speed and position of the inclined slit light in the vehicle left-right direction on the captured image at the time of detecting the pitching, and based on this gravity center position, The calibration apparatus according to claim 6, wherein the position in the left-right direction of the vehicle is adjusted. In addition to the inclined slit light, each light projecting means irradiates the horizontal slit light that extends in the horizontal direction and the vertical slit light that extends in the orthogonal direction of the horizontal slit light. Configured and possible
After the adjustment of the vehicle left-right direction on the imaging means side, the control means adjusts the horizontal position and vertical position on each light projecting means side so that the lateral slit light on the captured image continues in a straight line in the horizontal direction. Adjusting the direction relative position, and then adjusting the vertical position of the imaging center position on the imaging means side based on the vanishing point, which is the point where the tips of both longitudinal slit lights converge on the screen, The vertical position on the light projecting means side is adjusted so that the vertical interval between the imaging center position on the captured image and the horizontal slit light is a preset interval. Calibration equipment.

Images